What is the temperature of a neutral flame using oxygen and acetylene?

What is the temperature of a neutral flame using oxygen and acetylene?

• A. 3090 C (5600 F)
• B. 2900 C (5250 F)
• C. 2500 C (4520 F)
• D. 3500 C (6330 F)

Answer: (A)

Neutral means the gas mix is balanced, with just enough oxygen to burn the acetylene completely and no excess of either fuel or oxygen. In this balanced oxy-acetylene flame, the hottest part of the flame—the inner cone—reaches about 3090°C (roughly 5600°F). That temperature is the standard reference for a neutral acetylene–oxygen flame and explains why it’s chosen as the best answer. The other temperatures would correspond to flames that are either fuel-rich or oxygen-rich, which are not neutral and thus not the same combustion condition. Keep in mind that exact readings can vary with pressure, torch design, and where in the flame you measure, but around 3090°C is the typical neutral-flame temperature.

Neutral means the gas mix is balanced, with just enough oxygen to burn the acetylene completely and no excess of either fuel or oxygen. In this balanced oxy-acetylene flame, the hottest part of the flame—the inner cone—reaches about 3090°C (roughly 5600°F). That temperature is the standard reference for a neutral acetylene–oxygen flame and explains why it’s chosen as the best answer. The other temperatures would correspond to flames that are either fuel-rich or oxygen-rich, which are not neutral and thus not the same combustion condition. Keep in mind that exact readings can vary with pressure, torch design, and where in the flame you measure, but around 3090°C is the typical neutral-flame temperature.